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Yeast [FeFe]-hydrogenase-like protein Nar1 binds a [2Fe–2S] cluster
No full textNar1 is an essential eukaryotic protein proposed to function as an iron–sulphur (Fe/S) cluster trafficking factor in the cytosolic iron–sulphur protein assembly (CIA) machinery. However, such a role has remained unclear due to difficulties in purifying adequate amounts of cofactor-bound protein. The [FeFe]-hydrogenase-like protein has two conserved binding sites for [4Fe–4S] clusters but does not show hydrogenase activity in vivo due to the lack of an active site [2Fe]H cofactor. Here, we report a new preparation procedure for Nar1 that facilitated studies by UV-vis, EPR, and Mössbauer spectroscopies, along with native mass spectrometry. Nar1 recombinantly produced in E. coli contained a [4Fe–4S] cluster, bound presumably at site 1, along with an unexpected [2Fe–2S] cluster bound at an unknown site. Fe/S reconstitution reactions installed a second [4Fe–4S] cluster at site 2, leading to protein with up to three Fe/S cofactors. It is proposed that the [2Fe–2S] cluster occupies a cavity in Nar1 that is filled by the [2Fe]H cofactor in [FeFe]-hydrogenases. Strikingly, two of the Fe/S clusters were rapidly destroyed by molecular oxygen, linking Nar1 oxygen sensitivity in vitro to phenotypes observed previously in vivo. Our biochemical results, therefore, validate a direct link between cellular oxygen concentrations and the functioning of the CIA pathway. These advances also now allow for the pursuit of in vitro Fe/S cluster transfer assays, which will shed light on Fe/S trafficking and insertion by CIA components
2nd FOSsure Project meeting: Results from the bridge traffic monitoring campaign
No full textWe present distributed fiber optic results from the traffic monitoring measurement campaign on a newly constructed bridge in Brandenburg, which took place on 01.10.2025. Specifically, we employed a distributed acoustic sensing (DAS) system patented and developed by BAM and made use of optical fibers, which were embedded in the girders of the bridge. We show that our DAS system can capture vehicle flows along the bridge, including a) the number of vehicles, b) the number of axles, and c) estimates of vehicles' weight
Handgerät für den mobilen Einsatz zur Detektion von Sprengstoffspuren
No full textMithilfe des EXIST-Forschungstransfers wird ein tragbares und leicht zu bedienendes Handgerät auf der Basis von chemisch-optischen Sensoren entwickelt, welches kleinste Spuren von verschiedensten Sprengstoffen und Markern (z.B. TNT, C4, ANFO, TATP, DMDNB etc.) und reine Salze (z. B. Kaliumnitrat) sicher und ohne größere Querempfindlichkeiten detektieren kann. Das Gerät wurde in den letzten 10 Jahren bei der Bundesanstalt für Materialforschung und -prüfung (BAM) entwickelt und wird von der 2024 ausgegründeten Firma Noxoon GmbH in ein kommerzielles Gerät überführt.
Die Vorteile des Handgeräts sind die hohe Selektivität, die hohe Sensitivität, die schnelle Detektion in wenigen Sekunden bis zur Ergebnisanzeige sowie der schnelle und das geringe Gewicht des Gerätes von 900 g.
Neben den Vorteilen findet sich auch zahlreiche Alleinstellungsmerkmale in der Benutzung des Gerätes. So können z.B.
- reine Salze
- Sprengstoffe in Gegenwart von Wasser
- Sprengstoffe und Drogen in versiegelten Briefumschlägen detektiert werden.
Ein besonderes Alleinstellungsmerkmal ist, dass eine Reinigung des Handgeräts nach Messungen von stark kontaminierten Proben nicht notwendig ist.
Für den deutschsprachigen bzw. europäischen Raum existiert noch kein vergleichbares Gerät.
Das kommerzielle Gerät soll ab 2025 auf den Markt gebracht werden und wird einen wichtigen Beitrag zur öffentlichen Sicherheit und zum Umweltschutz leisten
Exploring the effects of accelerated ageing on lithium- and sodium-ion cells
No full textLithium-iron-phosphate (LFP) and sodium-ion batteries (SIBs) offer safe and cost-effective options for energy storage. In this study, the effects of continuous electrical stress, including high current loads and overdischarge, during cyclic ageing are investigated by tracing capacity loss and Coulombic efficiency during cycling of both cell types. Additionally, differential voltage analysis of pseudo open-circuit voltage discharges is utilised for degradation mode analysis. The results show that electrical stress accelerates degradation in both LFPs and SIBs, with high current rates potentially triggering plating or even cell failure in SIBs. Overdischarging primarily intensifies ageing by promoting accelerated solid electrolyte interphase growth
Impedance-based characterization of the overstress-related degradationin alkali metal-ion cells
No full textThe successful repurposing of degraded alkali metal-ion batteries in second-life applications is a vital step towards achieving a circular economy. While reusing aged cells is a promising way of mitigating their overall environmental footprint, it is crucial to anticipate their future safety and performance characteristics. Unfortunately, predicting these properties is a cumbersome task, essentially caused by limited knowledge of the interference of different degradation modes in the cells’ first life.
To still enable estimating of these parameters from a current state, the present study systematically investigates the impact of abusive conditions in an early phase of the cells’ life on their subsequent degradation behavior. For this purpose, individual lithium-ion and sodium-ion cells are initially stressed by different measures such as deep-discharging, high-temperature conditions, and deliberate combinations of the aforementioned methods. Electrochemical performance indicators are monitored during subsequent cycling of the cells, which provides insights into the interdependencies of different degradation modes induced by specific stress conditions. In this manner, it is clarified whether or not the total degradation can be determined by a convolution or a superposition of individual deterioration effects and thus, be described as a multidimensional state function.
This knowledge will finally contribute to a better understanding of the performance and safety behavior of degraded batteries which can help to successfully implement them into second-life applications
Prediction of weld pool and keyhole geometries in high-power laser beam welding through a physics-informed generative artificial intelligence approach
No full textThe weld pool and keyhole geometries are critical characteristics in evaluating the stability of the high-power laser beam welding (LBW) process and determining the resultant weld quality. However, obtaining these data through experimental or numerical methods remains challenging due to the difficulties in experimental measurements and the high computational demands of numerical modelling. This paper presents a physics-informed generative approach for predicting weld pool and keyhole geometries in the LBW process. With the help of a well experimentally validated numerical model considering the underlying physics in the LBW, the geometries of the weld pool and keyhole under various welding conditions are calculated, serving as the dataset of the generative model. A Conditional Variational Autoencoder (CVAE) model is employed to generate realistic 2D weld pool and keyhole geometries from the welding parameters. We utilize a β-VAE model with the Evidence Lower Bound (ELBO) loss function and include Kullback-Leibler divergence annealing to better optimize model performance and stability during training. The generated results show a good agreement with the ground truth from the numerical simulation. The proposed approach exhibits the potential of physics-informed generative models for a rapid and accurate prediction of the weld pool geometries across a diverse range of process parameters, offering a computationally efficient alternative to full numerical simulations for process optimization and control in laser beam welding processes
Thermally Robust 1D Cu(I) Phosphonate Coordination Polymer Exhibiting Enhanced Proton Conductivity via Humidity‐Driven Pathways
No full textThe development of thermally stable solid-state proton conductors (SSPCs) is crucial for advancing energy-conversion devices such as proton-exchange membrane fuel cells (PEMFCs). In this work, we report the solvothermal synthesis and characterization of a novel, 1D Cu(I) coordination polymer, {Cu(ADP)0.5(BPY)}n (BAM-5), based on anthracenediylphosphonate (H2ADP) and 4,40 -bipyridine (BPY). Single-crystal X-ray diffraction revealed that BAM-5 crystallizes in the triclinic space group P1 and shows a 1D ladder structure connected by the H2ADP and organic BPY linkers, which is assembled into a 2D layer via O−H···O hydrogen bonding interactions between uncoordinated oxygen and the O−H of the phosphonate group. Thermogravimetric and dynamic water sorption analysis demonstrated exceptional thermal robustness of BAM-5 until 230°C and notable water affinity. Proton conductivity measurements found increasing proton conductive properties with increasing temperature and relative humidity.The latter is correlated with the material’s water uptake since the structure itself does not contain any permanent lattice water molecules. A maximum proton conductivity of 6.6 × 10−6 S cm−1 was found at 80°C and 98% RH. To the best of our knowledge, no dense, nonporous 1D coordination polymer without lattice or coordinated solvent molecules has shown comparable proton con� ductivity. The high activation energy suggests a combination of both, a Grotthuss-type proton hopping through the hydrogen� bonded framework, and a vehicular process, in which protons are carried along with absorbed water molecules
Active Site Determination in Pyrolyzed M-N-C Electrocatalysts by Gas-sorption
No full textMetal and nitrogen-doped carbons (M-N-Cs) with M-N4 moieties as the generally accepted active sites, have gradually reached promising levels of activity towards crucial electrochemical reactions like the oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR). Even the metal-free counterparts, the nitrogen-doped carbons (NDCs), are common and well-studied electrocatalysts for ORR in alkaline media. In
these disordered porous materials, the characterization and quantification of (M)N4 sites can be challenging and time-consuming, with many spectroscopic methods drastically overestimating their site accessibility for catalytic applications. In this study, we explore an alternative approach towards active site characterization and quantification in M-N-Cs based on multi-Langmuir analysis of CO2-sorption isotherms at low pressures, with support fromelectronic DFT calculations
Simulation of functional ageing towards failure prediction of dental restorations - Investigating the Crown-Cement-Tooth Complex (CCTC)
No full textDental crown restorations are the most common type of indirect restoration in Germany, with over 5 million crowns placed annually. Clinical complications such as debonding and crown fractures cannot yet be adequately correlated with cement ageing processes. The SimuCrown project systematically investigates the ageing mechanisms of the crown–cement–tooth complex (CCTC) while also validating the in vitro methodology itself. This interdisciplinary cooperation combines experimental ageing simulation (Charité), computer-aided finite element method based simulation (TU Berlin), and high-resolution structural analysis using synchrotron-based X-ray refraction radiography (SXRR) on BAMline at BESSY II (BAM)
Unravelling the evolution of wood-feeding in termites with 47 high-resolution genome assemblies
No full textTermites are a lineage of social cockroaches abundant in tropical ecosystems where they are key decomposers of organic matter. Despite their ecological significance, only a handful of reference-quality termite genomes have been sequenced, which is insufficient to unravel the genetic mechanisms that have contributed to their ecological success. Here, we perform sequencing and hybrid assembly of 45 taxonomically and ecologically diverse termites and two cockroaches, resulting in haplotype-merged genome assemblies of 47 species, 22 of which were near-chromosome level. Next, we examine the link between termite dietary evolution and major genomic events. We find that Termitidae, which include ~80% of described termite species, have larger genomes with more genes and a higher proportion of transposons than other termites. Our analyses identify a gene number expansion early in the evolution of Termitidae, including an expansion of the repertoire of CAZymes, the genes involved in lignocellulose degradation. Notably, this expansion of genomes and gene repertoires coincided with the origin of soil-feeding in Termitidae and remained unchanged in lineages that secondarily reverted to a wood-based diet. Overall, our sequencing effort multiplies the number of available termite genomes by six and provides insights into the genome evolution of an ancient lineage of social insects